What are the chances of pregnancy on depo-provera provera (medroxyprogesterone)? been on it for 4 months, deep mood swings and extreme nausea&bloating!

Unlikely: You may have side effects from the medication, or an unrelated illness, but it's very unlike that you would ovulate if properly dosed with depo-provera.

Pregnancy unlikely: Depotprovera is among the most effective birth control methods. However, it occasionally comes with side effects, some of which you are unfortunately experiencing: the mood swings and the nausea and bloating, sometimes women complain of hair loss and extreme weight gain (30 kg +). The only remedy is to stop the depotprovera.